I installed Win 7, with UAC enabled.
I had an existing xampp installation. I simply re-installed 1.7.7 over the existing. Everything worked fine afterwards; could get to all my sites in development.
Then I had to re-install Win 7, and this time I set UAC disabled.
Re-installed xampp over the previous install.
http://localhost/xampp gives me the xampp opening page
http://localhost/mywebsite gives me the object not found error
I also reset permissions, saved my data, reloaded again and get the same error.